TWI465911B - Print system and its alignment structure of wireless data transmission interface - Google Patents

Description

Print system and its alignment structure of wireless data transmission interface

This invention relates to a printing system, and more particularly to an electronic paper (ePaper) printing system that does not require a battery.

An eBook or an eReader can be implemented in different technologies such as a smart phone or a tablet. Current e-books or e-readers require batteries to provide operating power, such as backlights, liquid crystal displays, and the like. The battery inside the e-book or e-reader can provide the operating power required for the e-book or e-reader. However, the weight and volume of the battery may make it difficult for the user to carry an e-book or an electronic reader. Furthermore, in some situations, such as during take-off/landing of an aircraft, an e-book or e-reader is required to shut down and cannot continue reading. If the display content can be printed, the user can read the e-book without interruption even when the electronic device is required to be turned off.

The present invention provides a printing system having a host and a printing device. The printing device does not need to be configured with a battery to provide a user to read the display content of the electronic paper (ePaper).

The present invention provides a registration structure for a wireless data transfer interface between a host and a printing device. When the host transmits the printed material and the operating power to the printing device, the alignment structure can align the coil of the host with the coil of the printing device.

Embodiments of the present invention provide a printing system including a host and a printing device. The host includes a first coil, a first modulation unit, and a processing unit. The processing unit outputs the print data to the first modulation unit. The first modulation unit carries the print data in the first alternating current electrical energy, and outputs a second alternating current electrical energy carrying the printed data to the first alternating current. The first coil converts the second alternating current electrical energy into radio energy. The printing device includes a second coil, a second modulation unit, at least one electronic paper, and a control driving unit. The second coil is configured to receive radio energy provided by the host and carrying the printed data. The radio received by the second modulation unit from the coil is capable of demodulating print data and operating electrical energy, wherein the operational electrical energy is used as an energy source for the printing device. The control driving unit receives the print data provided by the second modulation unit, and drives the at least one electronic paper to display the print data.

Embodiments of the present invention provide a printing apparatus including a coil, a modulation unit, at least one electronic paper, and a control driving unit. The coil receives the radio energy provided by an external host that can carry the printed material. The modulation unit is coupled to the coil. The radio received by the modulation unit from the coil can demodulate the print data and an operational power, wherein the operational power is used as an energy source for the printing device. The control driving unit is coupled between the modulation unit and the at least one electronic paper. The control driving unit receives the print data and drives the at least one electronic paper to display the print data.

Embodiments of the present invention provide a host, including a coil, a processing unit, and a modulation unit. The processing unit outputs the print data. The modulation unit is coupled to the processing unit and the coil. The modulation unit carries the print data in the first alternating current electrical energy, and outputs the second alternating current electrical energy carrying the printed data to the coil. Wherein the coil converts the second alternating current electrical energy into radio energy, and the radio can wirelessly transmit an operating electrical energy to a printing device as an energy source of the printing device, and the printed material can be printed by the radio Transfer to the printing device.

The embodiment of the present invention provides a aligning structure of a wireless data transmission interface, including a first housing, a first coil, a plurality of magnetic units, a second housing, a second coil, and a positioning ring. The first coil and the plurality of magnetic units are disposed inside the first housing. The plurality of magnetic units are disposed around the first coil. The second coil and the positioning ring are disposed on the inner side of the second housing. The positioning ring is disposed around the second coil. Wherein, when the first casing approaches the second casing, the first coil and the second coil are aligned with each other by a magnetic force between the plurality of magnetic units and the positioning ring.

Based on the above, in the embodiment of the present invention, the printing data and the operating power are transmitted to the printing device by the host through the wireless data transmission interface, so the printing device can print/update the printed data on the electronic paper without configuring the battery. After the print/update is completed, the electronic paper can keep the display content even if the host is removed/turned off. Therefore, even when the electronic device is required to be turned off, the user can read the display content of the electronic paper without interruption. Moreover, since the printing apparatus can be configured without a battery, and based on the flexibility and portability of the electronic paper, the printing apparatus using the electronic paper can provide a user who is more comfortable and more close to the reading feeling of the conventional paper.

The above described features and advantages of the present invention will be more apparent from the following description.

Compared with liquid crystal displays, ePaper's flexibility, portability and power saving characteristics are more suitable for implementing e-books or electronic readers. E-books or e-readers implemented with electronic paper can provide users with a more comfortable and close reading experience of traditional paper. After the update of the display content of the electronic paper is completed, the electronic paper can maintain its display content without operating the power until the display content is updated next time. This embodiment will explain a printing system 100 using electronic paper. 1 is a functional block diagram illustrating a printing system 100 in accordance with an embodiment of the present invention. The printing system 100 includes a host 110 and a printing device 120.

Depending on the design requirements, host 110 can be a telephone, a personal computer, a notebook, a tablet, an e-book reader, a camera, or other electronic device that requires output/printing of text and/or images. In other embodiments, host 110 can also be any public communication/sales machine, such as a public telephone, vending machine, and the like. Taking the vending machine as an example, the host 110 may be an e-book providing device to provide/sell an e-book to the user.

The host 110 includes a processing unit 111, a first modulation unit 112, a power unit 113, and a first coil 114. The processing unit 111 outputs the print data to the first modulation unit 112. The power unit 113 can be used as an energy source of the host 110 to provide operational power required by the internal components of the host 110 (eg, the processing unit 111 and the first modulation unit 112). The power unit 113 can be a power supply, an adapter, a battery, a regulator, and/or other power supply circuitry. The power unit 113 outputs a stable first DC power DC1 to the first modulation unit 112. The first modulation unit 112 can convert the DC power DC1 into the first AC power (described later). This first alternating current power will be used as a carrier to transfer the printed material to the printing device 120.

The first modulation unit 112 carries the print data provided by the processing unit 111 in the first alternating current power using any modulation technique, such as the modulation technique well known in the communication field, and then outputs the print. The second alternating current electrical energy AC2 of the data (ie, the modulated first alternating current electrical energy) is supplied to the first coil 114. The first coil 114 can convert the second alternating current power AC2 into radio energy EM. In the present embodiment, the axial direction of the first coil 114 is substantially perpendicular to the first housing 116 of the main body 110 (described later), so that the electromagnetic field (radio energy EM) generated by the first coil 114 can be emitted approximately vertically. / Injection into the first housing 116.

The printing device 120 includes a second coil 121, a second modulation unit 122, a control driving unit 123, and at least one electronic paper 124. The display medium of the electronic paper 124 can use a bistable (or multi-stable) display medium, such as electronic ink (E-Ink), electrofluidics, cholesteric liquid crystal, electrophoretic display (electro -phoretic display, EPD) or electrowetting display (EWD).

The second coil 121 is configured to receive the radio energy EM provided by the host 110 and carrying the print data. In the present embodiment, the axial direction of the second coil 121 is substantially perpendicular to the second housing 126 of the printing device 120 (described later). When the printing device 120 approaches the host 110 (even when the outer surface of the first housing 116 of the main body 110 touches the outer surface of the second housing 126 of the printing device 120) such that the second coil 121 approaches the first coil 114, A coil 114 forms a transformer similar to the second coil 121. Therefore, the second coil 121 can sense/receive an electromagnetic field (radio energy EM) generated by the first coil 114, and correspondingly generate a third alternating current power AC3. The second modulation unit 122 demodulates the print data and the operating power VDD from the radio energy EM received by the second coil 121. This operational power VDD can serve as an energy source for internal components of the printing device 120 (eg, control drive unit 123). Since the operating power VDD of the printing device 120 is provided by the host 110, the printing device 120 may not need to configure a battery or an adapter to reduce the volume and weight of the printing device 120.

The control driving unit 123 receives the print data provided by the second modulation unit 122, and then drives the electronic paper 124 to display the print data. Based on the different display media of the electronic paper 124, the control driving unit 123 can correspondingly employ any driving technology, such as a driving technology well known in the art of electronic paper, and therefore will not be described herein.

With the help of integrated circuit technology, the printing device 120 can be as thin as possible, even light, thin, and flexible like paper. For example, FIG. 2 is a schematic diagram showing an application scenario of the printing system 100 of FIG. 1 according to an embodiment of the invention. In the present embodiment, the host 110 is implemented as a smart phone, and the printing device 120 is implemented as a single sheet of electronic paper (which looks like a piece of plastic paper). The printing device 120 is not equipped with a battery. Referring to FIGS. 1 and 2 , a first coil 114 is disposed on the back surface of the host 110 . When the host 110 is placed over the second coil 121 of the printing device 120, the printing device 120 can receive the wireless power EM provided by the host 110 and acquire the operating power VDD from the wireless energy EM. Therefore, the printing device 120 without battery or other energy source can operate various functions using the operating power VDD provided by the host 110, including demodulating the print data from the wireless power EM, and printing/displaying the printed material on the electronic paper 124. After the printing/display operation is completed, even if the host 110 is removed/shutdown and the printing device 120 loses the operating power VDD, based on the characteristics of the bistable (or multi-stable) display medium, the electronic paper 124 remains corresponding to Print the display of the material.

The printing apparatus 120 of the above embodiment is configured with a single sheet of electronic paper, but the implementation thereof is not limited thereto. A person skilled in the art can implement the printing apparatus 120 in any appearance and any structure according to product design requirements. For example, FIG. 3 is a schematic diagram showing an application scenario of the printing system 100 of FIG. 1 according to another embodiment of the present invention. In the present embodiment, the printing apparatus 120 is configured with a plurality of electronic papers 124, such as electronic papers 124-1, 124-2, 124-3, ..., 124-n. The electronic papers 124-1~124-n are bound to look like books. The second coil 121 of the printing device 120 is disposed at the lower left corner of the cover (or back cover) electronic paper 124-n. When the first coil 114 on the back side of the host 110 approaches the second coil 121 of the printing apparatus 120 (as shown in FIG. 3), the printing apparatus 120 can receive the radio energy EM supplied from the host 110 and acquire the operation from the radio energy EM. Power VDD. The user can use the host 110 to download print data (such as an e-book) from the remote end to the host 110, and then use the host 110 to print/display the print data on the electronic papers 124-1~124-n. Therefore, even when the host 110 is required to be turned off, the user can read the contents of the electronic papers 124-1 to 124-n without interruption. Furthermore, since the printing device 120 does not need to be configured with a battery, and based on the flexibility and portability of the electronic papers 124-1 to 124-n, the printing device 120 using the electronic papers 124-1 to 124-n can provide a user. More comfortable and more close to the traditional paper reading experience.

FIG. 4 is a block diagram showing the function of the host 110 according to another embodiment of the present invention. This embodiment can refer to the related description of FIG. 1. Different from the embodiment shown in FIG. 1, the host 110 shown in FIG. 4 further includes a current sensor 115. Referring to FIG. 4 , the first modulation unit 112 includes a DC to AC converter 410 and a first mixer 420 . The DC AC converter 410 converts the DC power DC1 into the first AC power AC1. The first mixer 420 can be a modulator. The first mixer 420 is coupled to the DC AC converter 410 and the processing unit 111. The first mixer 420 carries the print data provided by the processing unit 111 in the first alternating current power AC1 using any modulation technique, such as a modulation technique well known in the communications arts.

The current sensor 115 can detect the amount of current of the DC-AC converter 410, for example, detecting the amount of input current of the DC-AC converter 410 (that is, the amount of current of the DC power DC1), or detecting the DC-AC converter 410. The amount of current output (that is, the amount of current of the first alternating current power AC1). When the printing device 120 acquires the operating power VDD by the radio energy EM of the first coil 114, the amount of current of the DC-AC converter 410 increases correspondingly. Therefore, the current sensor 115 can detect whether the printing device 120 can receive the wireless power EM by detecting the amount of current of the DC-AC converter 410. The current sensor 115 transmits the detection result to the processing unit 111. Based on the detection result of the current sensor 115, the processing unit 111 can know when the printing device 120 receives the wireless power EM. When the printing device 120 receives the wireless power EM, the processing unit 111 can output the print data to the first mixer 420. After the first mixer 420 receives the print data, the first mixer 420 carries the print data in the first alternating current power AC1 and outputs the second alternating current power AC2 carrying the print data to the first coil 114.

FIG. 5 is a functional block diagram illustrating a printing apparatus 120 in accordance with another embodiment of the present invention. This embodiment can refer to the related description of FIG. 1. Different from the embodiment shown in FIG. 1, the printing device 120 shown in FIG. 5 further includes a current sensor 125. Referring to FIG. 5 , the second modulation unit 122 includes a second mixer 510 , a rectifier circuit 520 , and a low-pass filter 530 . The second mixer 510 receives the radio energy EM (ie, the third alternating current power AC3) from the first coil 114 through the second coil 121, and demodulates the radio energy EM out of the print data and the alternating current AC4. The rectifier circuit 520 is coupled to the second mixer 510 to receive the alternating current AC4, and to rectify the alternating current AC4 into a direct current DC2. The rectifier circuit 520 can be a half wave rectifier or a full wave rectifier, such as a bridge rectifier.

The low pass filter 530 is coupled to the rectifier circuit 520. The low pass filter 530 receives the direct current DC2 and filters the high frequency component of the direct current DC2 to obtain the operating power VDD. The current sensor 125 can detect the amount of current of the low pass filter 530, for example, detecting the amount of input current of the low pass filter 530 (that is, the amount of current of the direct current DC2), or detecting the low pass filter 530. The amount of current output (that is, the amount of current that operates the power VDD). By the current amount determination of the low pass filter 530, the current sensor 125 can know whether the operating power VDD currently obtained from the wireless power EM is sufficient to satisfy the power demand of the printing device 120 to operate stably. The current sensor 125 transmits the detection result to the control driving unit 123. According to the detection result of the current sensor 125, the control driving unit 123 can know when the operating power VDD is ready. When the operating power VDD is ready, the control driving unit 123 can receive the demodulated print data from the second mixer 510 and then drive the electronic paper 124 to display the print data.

The outer surface of the housing of the printing device 120 and/or the main body 110 may be printed with a mark to guide the user to align the first coil 114 and the second coil 121 by moving the printing device 120 and/or the host 110. Alternatively, an alignment structure is disposed inside the casing (or outside the casing) of the printing apparatus 120 and/or the main body 110. For example, FIG. 6 is a perspective view showing the alignment structure of the wireless data transmission interface between the host 110 and the printing device 120 in the printing system 100 of FIG. 1 according to the embodiment. Referring to FIG. 6, the first housing 116 represents the outer casing of the main body 110, and the second housing 126 represents the outer casing of the printing device 120.

The first coil 114 and the plurality of magnetic units 117 are disposed inside the first housing 116 (ie, disposed inside the host 110). The magnetic unit 117 is disposed around the first coil 114. The second coil 121 and the positioning ring 127 are disposed inside the second casing (that is, disposed inside the printing device 120). The positioning ring 127 is disposed around the second coil 121 as shown in FIG. The material of the positioning ring 127 includes ferromagnetic materials such as metals such as iron, nickel, and cobalt. The plurality of magnetic units 117 are permanent magnets or electromagnets. Therefore, when the first housing 116 approaches the second housing 126, the first coil 114 and the second coil 121 are aligned with each other by the magnetic force between the plurality of magnetic units 117 and the positioning ring 127.

If the magnetic unit 117 is implemented with an electromagnet, the processing unit 111 can decide whether to trigger the magnetic unit 117 to generate a magnetic field. The processing unit 111 disables the magnetic unit 117 while the print material is not required to be transferred/printed to the electronic paper 124. When the print data needs to be transferred/printed to the electronic paper 124, the processing unit 111 triggers the magnetic unit 117 to generate a magnetic field to assist the first coil 114 and the second coil 121 to be more accurately aligned with each other.

In another embodiment, the host 110 is internally configured with a reed switch (REED SWITCH). Whether the positioning ring 127 is close to the host 110 will determine the conduction state of the reed switch. Therefore, the processing unit 111 can determine whether the printing device 120 is close to the host 110 according to the conduction state of the reed switch. When the conductive state of the reed switch instructs the printing device 120 to approach the host 110, the processing unit 111 triggers the magnetic unit 117 to generate a magnetic field to assist the first coil 114 and the second coil 121 to more accurately align with each other.

FIG. 7 is a flow chart showing the host 110 performing the electronic paper printing operation according to an embodiment of the invention. In step S710, the host 110 first loads the print data. For example, the host 110 can request a remote web server to download a web page, an e-book, a photo, or other type of printed material via the Internet. For example, if the host 110 is a digital camera or other electronic device having a shooting function, the host 110 can capture a target image (ie, print data) by using an image sensing circuit.

After the host 110 prepares the print data, the host 110 may proceed to step S720 to start the electronic paper printing operation described in the previous embodiments. When the user brings the host 110 and the printing device 120 closer to each other, the reed switch inside the host 110 changes the on state correspondingly. When the conduction state of the reed switch instructs the printing apparatus 120 to approach the host 110, the processing unit 111 may proceed to step S730 to trigger a plurality of magnetic units 117 (electromagnets or coils) to generate a magnetic field. The magnetic force between the plurality of magnetic units 117 inside the main body 110 and the inner positioning ring 127 of the printing device 120 can assist the first coil 114 and the second coil 121 to more accurately align with each other.

In the case where the conduction state of the reed switch indicates that the printing device 120 is close to the host 110, and in the case where the current sensor 115 detects that the current amount of the DC-AC converter 410 is greater than a certain threshold value, the processing unit Step 111 begins to transfer the print material to the first modulation unit 112. The first modulation unit 112 and the first coil 114 transmit the radio energy EM carrying the print material to the second coil 121 of the printing device 120.

In the process of transmitting the print material, the processing unit 111 determines at any time whether or not the electronic paper print operation is ended (step S750). The electronic paper printing operation has not ended yet, and the processing unit 111 returns to step S720 to continue the electronic paper printing operation. For example, in a case where the conduction state of the reed switch instructs the printing device 120 to approach the host 110, and in the case where the current sensor 115 detects that the current amount of the DC-AC converter 410 is greater than a certain threshold, the processing unit 111 Continue with the e-paper printing operation. If the on state of the reed switch indicates that the printing device 120 is away from the host 110, or if the current sensor 115 detects that the amount of current of the DC to AC converter 410 is less than a certain threshold, the processing unit 111 The e-paper printing operation will be resumed.

When the user issues an instruction to stop printing, or when all the print data has been transferred, the processing unit 111 notifies the electronic paper (printing device 120) electronic paper printing through the first modulation unit 112 and the first coil 114. The operation has ended. Next, the processing unit 111 proceeds to step S760 to turn off the current of the plurality of magnetic units 117, that is, stop triggering the electromagnet.

FIG. 8 is a flow chart showing the electronic paper (printing device 120) performing the electronic paper printing operation according to an embodiment of the present invention. When the host 110 is away from the printing device 120, the printing device 120 is in an unpowered state due to loss of energy (step S810). When the first coil 114 of the host 110 approaches the second coil 121 of the printing apparatus 120, the printing apparatus 120 can obtain the operational power VDD from the wireless power EM received by the second coil 121 (step S820). Next, the control driving unit 123 detects whether the current amount of the low-pass filter 530 is greater than a certain threshold value through the current sensor 125, that is, whether the operating power VDD obtained from the wireless power EM is stable (step S830). When the current sensor 125 detects that the current amount of the low-pass filter 530 is greater than a certain threshold, the control driving unit 123 sends the second modulation unit 122 and the second coil 121 to notify the host 110 to start transmitting the printed data. . At this point, the control driving unit 123 can receive the print data provided by the host 110 through the second modulation unit 122 and the second coil 121 (step S840), and drive the electronic paper 124 to display the print data (step S850).

In summary, in the above embodiments, the host 110 transmits the print data and the operating power VDD to the printing device 120 through the wireless data transmission interface. Since the operating power VDD is provided by the host 110 through the wireless data transmission interface, the printing device 120 can print/update the printed material on the electronic paper 124 without configuring the battery. After the printing/update is completed, the electronic paper 124 can still maintain its display content even if the host 110 is removed or turned off. In particular, in the case where the electronic device must be turned off, the user can print/display the printed material (for example, an electronic book) on the electronic paper 124 in advance, and even if the host 110 and the printing device 120 are powered off, the user can continue uninterruptedly. Read the printed material that has been printed on the electronic paper 124. Moreover, since the printing device 120 can be configured without a battery, and based on the flexibility and portability of the electronic paper 124, the printing device 120 using the electronic paper 124 can provide a user's reading comfort that is more comfortable and closer to conventional paper.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100. . . Printing system

110. . . Host

111. . . Processing unit

112. . . First modulation unit

113. . . Power unit

114. . . First coil

115, 125. . . Current sensor

116. . . First housing

117. . . Magnetic unit

120. . . Printing device

121. . . Second coil

122. . . Second modulation unit

123. . . Control drive unit

124, 124-1, 124-2, 124-3, 124-n. . . Electronic paper

126. . . Second housing

127. . . Locating ring

410. . . DC AC converter

420. . . First mixer

510. . . Second mixer

520. . . Rectifier circuit

530. . . Low pass filter

AC1, AC2, AC3. . . AC power

AC4. . . Alternating current

DC1. . . DC power

DC2. . . DC

EM. . . Radio energy

VDD. . . Operating energy

S710~S760, S810~S850. . . step

1 is a functional block diagram illustrating a printing system in accordance with an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an application scenario of the printing system shown in FIG. 1 according to an embodiment of the invention.

FIG. 3 is a schematic diagram showing an application scenario of the printing system shown in FIG. 1 according to another embodiment of the present invention.

FIG. 4 is a block diagram showing the function of a host according to another embodiment of the present invention.

FIG. 5 is a block diagram showing the function of a printing apparatus according to another embodiment of the present invention.

FIG. 6 is a perspective view showing the alignment structure of the wireless data transmission interface between the host and the printing device in the printing system shown in FIG. 1 according to the embodiment.

FIG. 7 is a flow chart showing a host performing the electronic paper printing operation according to an embodiment of the invention.

FIG. 8 is a flow chart showing an electronic paper (printing apparatus) performing the electronic paper printing operation according to an embodiment of the present invention.

110. . . Host

120. . . Printing device

124. . . Electronic paper

Claims (9)

A printing system comprising: a host comprising a first coil, a plurality of electromagnets disposed around the first coil, a reed switch, a first modulation unit and a processing unit; and a printing device The printing device includes a second coil, a positioning ring disposed around the second coil, a second modulation unit, at least one electronic paper, and a control driving unit, wherein the material of the positioning ring comprises a ferromagnetic substance. The conduction state of the reed switch is determined according to whether the positioning ring is close to the host. If the conduction state of the reed switch indicates that the positioning ring is close to the host, the processing unit triggers the electromagnets to generate a magnetic field to assist the first The first coil is output to the first modulation unit a second alternating current power of the printed material to the first coil, and the first coil converts the second alternating current electrical energy into a wireless energy if the reed switch The pass state indicates that the positioning ring is not close to the host, the control unit stops triggering the electromagnets to generate the magnetic field, and stops outputting the print data, and the second coil is configured to receive the radio provided by the host and carrying the print data. The radio that the second modulation unit receives from the coil can demodulate the print data and an operating power as an energy source of the printing device. The control driving unit receives the print data provided by the second modulation unit and drives the at least one electronic paper to display the print data. The printing system of claim 1, wherein the first modulation unit comprises: a DC current converter that converts the DC power into the first AC power; and a first mixer coupled And the DC converter and the processing unit, the first mixer loading the print data in the first AC power and outputting the second AC power carrying the print data to the first coil. The printing system of claim 1, wherein the second modulation unit comprises: a second mixer, receiving the wireless energy from the first coil through the second coil, and the wireless energy Demodulating the printed data and an alternating current; a rectifying circuit coupled to the second mixer to receive the alternating current, and rectifying the alternating current into a direct current; and a low pass filter coupled to the rectifying A circuit receives the DC current and filters the DC current to obtain the operating energy. The printing system of claim 1, wherein the host is a phone, a computer, a camera or an e-book providing device. A host includes: a coil; a plurality of electromagnets disposed around the coil; a reed switch, wherein the conductive state of the reed switch is determined according to whether the positioning ring is close to the host; a processing unit; and a modulation unit coupled to the processing unit and the coil, wherein the magnetic spring The conduction state of the switch indicates that the positioning ring is close to the host, the processing unit triggers the electromagnets to generate a magnetic field to assist the first coil and the second coil to accurately align with each other, and the processing unit outputs a print data to the first a modulation unit, the modulation unit loading the print data in a first alternating current electrical energy and outputting a second alternating current electrical energy carrying the printed material to the coil, wherein the coil converts the second alternating current electrical energy into a Radio capable of wirelessly transmitting an operational power to a printing device as an energy source for the printing device, and transmitting the printed material to the printing device by the wireless; and if the reed switch The conduction state indicates that the positioning ring is not close to the host, and the control unit stops triggering the electromagnets to generate the magnetic field, and stops outputting the printed data. The host device of claim 5, wherein the modulation unit comprises: a DC current converter that converts the DC power into the first AC power; and a mixer coupled to the DC AC conversion And the processing unit, the mixer loading the print data in the first alternating current electrical energy and outputting the second alternating current electrical energy carrying the printed material to the coil. The host computer of claim 5, wherein the host is a phone, a computer, a camera or an e-book providing device. The alignment structure of the wireless data transmission interface includes: a first housing; a first coil disposed on the inner side of the first housing; a reed switch; and a plurality of electromagnets disposed on the first housing The inner side is disposed around the first coil; a second housing; a second coil disposed on the inner side of the second housing; and a positioning ring disposed on the inner side of the second housing and configured Around the second coil, wherein the material of the positioning ring comprises a ferromagnetic substance, wherein the conductive state of the reed switch is determined according to whether the positioning ring is close to the host, wherein if the conductive state of the reed switch indicates the positioning The coil is proximate to the mainframe, and the electromagnets are triggered to generate a magnetic field to assist the first coil and the second coil to accurately align with each other. For example, in the alignment structure of the wireless data transmission interface described in claim 8, wherein the material of the positioning ring comprises a ferromagnetic substance.